Custard Pi Combos for the Raspberry Pi

If a particular Custard Pi does not have all the right inputs and outputs, then it’s possible to combine more than one. This post looks at the various combinations that are possible. (It's a chapter extraction from the new book 'Raspberry Pi with Custard' which is available from Amazon.)

Monitoring Energy usage with the LED Pulse Sensor from Crucible Technologies

With winter coming, and all the energy scares in the news, I was keen to start monitoring the power we were using. I had always intended designing my own system with the LED Pulse Sensor and the Raspberry Pi, but had never got round to it. So I thought I'd quickly rig up soemthing using the Meter Logger from Crucible Technologies. Took me around half an hour to set it all up.

Switching appliances ON and OFF remotely by e-mail with the Raspberry Pi and Mains Switch Widget #2

Switching appliances ON and OFF using e-mails. This part of this multi-part post looks at logging in and reading e-mails from a gmail account and using the subject field to switch an appliance ON and OFF.

Switching appliances ON and OFF remotely by e-mail with the Raspberry Pi and Mains Switch Widget #1

Having designed the Mains Switch Widget, my next challenge was to turn appliances ON and OFF from outside the house. I investigated Twitter and texts as a means of doing this but finally settled on using e-mails to control the appliances. This multi part post outlines the various steps along the way.

Electrical Safety in product design

If your product is going to be powered by batteries or use an external plug top supply, then this subject is not a priority for you. However a well rounded electronics engineer should have an appreciation of electrical safety in a product. If your product is going to use mains voltage, then it is vital that you have a good understanding of this.

Raspberry Pi B+ GPIO compatibility

There are many plug in boards for the Raspberry Pi model B (2 x 13 pin connector) which are now not compatible with the Model B+ as this has 2 x 20 pin connector. Even if they plug in, they can interfere with some of the components as the position of the GPIO has moved.

Fortunately the entire Custard Pi range is compatible with the Model A, B and the Model B+.

Mains Switch Widget for Home Automation

The Mains Switch Widget allows the user to switch 230V or 110V mains ON and OFF to mains powered devices from microcontrollers like the PIC and the Arduino or from single board computers like the Raspberry Pi and the Beaglebone. All the safety requirements are designed-in to prevent any faults resulting in a fire. A plastic enclosure is supplied to prevent the user from accidentally touching the mains voltage.

Fixing switch bounce in firmware

I have been involved in many products where a poor understanding of switch bounce has led to a design that had problems in the field. To learn how to deal with this the engineer has to understand exactly what switch bounce is. Although I refer to this as switch bounce, it relates to reading any input.

Custard Pi 8 project for the Raspberry Pi - Electronic Dice

This project is ideal for schools and colleges to demonstrate using the Raspberry Pi in an electronics project. It uses the GPIO and also can be used to teach students to solder conventional and SMT devices as well as wires.

Custom metal enclosures for products - an alternative to injection moulding

Many designers rush to injection moulding when designing enclosures for electronic products. Often there are many other alternative options. Here we consider custom metal enclosures with a case study  using the PAT-IT Portable Appliance Tester. More examples can be seen in the book "From Prototype to Product - a Practical Guide for Electronic Engineers".

Weighing scales project using a Load Cell and Custard Pi 3

This is an experimental project using a Load Cell and the Custard pi 3 to produce weighing scales. A circuit to amplify the signal and sample code is also presented.